SpringBoot 2 Actuator Endpoint

创建Maven 项目：

POM 中加入 actuator 依赖，来获取应用程序的实时运行数据。

  <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

POM全文如下：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.study</groupId>
  <artifactId>springboot-monitor</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
   <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
       <version>2.1.1.RELEASE</version>
        <relativePath />
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        



        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

    <build>

        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

创建启动类Application

package com.actuator.simple;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
     SpringApplication.run(Application.class, args);
    }
}

默认情况下，只有如下 3 个 actuator 端口暴露出来：

在application.yml 中，开启 shutdown 端点，并暴露 shutdown 、health 和 info端口：

server:
  port: 8090
management:
  endpoint: 
    shutdown:
      enabled: true
  endpoints:
    web:
      exposure:
        include: shutdown,health,info

调用 shutdown 端点：

在yaml 中配置暴露所有端点：

server:
  port: 8090
management:
  endpoint: 
    shutdown:
      enabled: true
  endpoints:
    web:
      exposure:
        include: "*"

在pom.xml 中加入如下security依赖：

               <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>

并配置保护Actuator Endpoint，开启HttpBasic, 并在application.yml 中创建role为ACTUATOR 的 User。

package com.actuator.simple;

import org.springframework.boot.actuate.autoconfigure.security.servlet.EndpointRequest;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@Configuration
public class ActuatorSecurity extends WebSecurityConfigurerAdapter{

    /* 
     * need to add http.csrf().disable(); to call actuator/shutdown successfully
     * https://stackoverflow.com/questions/50689032/spring-boot-actuator-shutdown-endpoint-forbidden
     */
    @Override
    protected void configure(HttpSecurity http) throws Exception {
    //protect all Actuator endpoints,such as actuator/health, actuator/info
    http.requestMatcher(EndpointRequest.toAnyEndpoint()).authorizeRequests().anyRequest().hasRole("ACTUATOR").and().httpBasic().and().csrf().disable();
    
    }
}

注意此处我们关闭了 CSRF protection,以使 POST /actuator/shutdown 方法得以执行，否则，调用

POST /actuator/shutdown 会得到403 Forbidden Error。

Cross Site Request Forgery Protection 
Since SpringBoot relies on Spring security's defaults, CSRF protection is turned by default. This means that the actuator endpoints that require a POST( SHUTDOWN and LOGGERS endpoints) PUT or DELETE will get a 403 forbidden error when the default security configuration is in use.

[Note]
It's recommended that disabling CSRF protection completely ONLY IF you are creating a service that is used by non-browser clients.

management.endpoint.health.show-details 的值默认是never,即不显示 health 端点的 details 信息。

当将 management.endpoint.health.show-details 设为 when_authorized 或 always 时，可看到health 端点的 details 信息。

此时，application.yml 如下：

server:
  port: 8090
management:
  endpoint: 
    health:
#     show-details: never(default) / when-authorized / always
      show-details: when-authorized 
    shutdown:
      enabled: true
  endpoints:
    web:
      exposure:
        include: shutdown,health,info
spring:
  security:
    user:
      name: xluffy
      password: 123
      roles: ACTUATOR

调用 /actuator/health ,并提供application.yml 中设定的用户名、密码，此时可看到health 端点的 details 信息

SpringBoot会根据classpath 中的依赖自动配置HealthIndicator: 例，如果在 pom.xml 中加入了如下Redis 依赖，并启动Redis Server，此时的 health 端点信息如下：

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
        </dependency>

此处，有3 个 HealthIndicator，分别是 HealthIndicator 、 DiskSpaceHealthIndicator 、RedisHealthIndicator

对于HealthIndicator 如果如下继承该类，

package com.actuator.simple;

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;
@Component
public class CustomHealth implements HealthIndicator {

    @Override
    public Health health() {
    
    return Health.outOfService().withDetail("msg", "服务中断...").build();
    }

}

则 Health 端点的信息如下：

当在application.yml 中加入

info:
  author:
    name: xluffy

以及配置build-info goal 时，

             <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                  <execution>
                    <goals>
                      <goal>build-info</goal>
                    </goals>
                  </execution>
                </executions>
            </plugin>

可以看到如下信息：

git-commit-id-plugin 可以将Git 信息暴露到 actuator/info 端口，前提是需要build project（maven clean  package）
Add this to plugins section of pom.xml. maven will generate this file during build ./target/classes/git.properties. 
Spring will read contents of this file and include it in the response of /actuator/info
此时的application.yml 是：

server:
  port: 8090
management:
  info:
    git:
#      mode: full
      mode: simple
  endpoint: 
    health:
#     show-details: never(default) / when-authorized / always
      show-details: when-authorized 
    shutdown:
      enabled: true
  endpoints:
    web:
      exposure:
        include: shutdown,health,info
spring:
  security:
    user:
      name: xluffy
      password: 123
      roles: ACTUATOR
info:
  author:
    name: xluffy

<plugin> 
<groupId>pl.project13.maven</groupId>
<artifactId>git-commit-id-plugin</artifactId>
</plugin>